This invention relates to gain enhancement, particularly to enhancement of a data receiver circuit for high speed data reception.
Amplification is used to amplify incoming signals of variable (small) amplitude to rail-to-rail logic signals. However, variation in signal se can occur, as by losses in the signal path. As a result, the amplified signal can vary in strength.
As stated above, due to various reasons, the input signal can vary in strength, and so the amplified signal varies in strength. In many applications, typical input signals at 400 Mbits/S (2.5 ns bit cell time) have an amplitude of 200 mV, with occasional smaller pulses of  less than 110.mV. Ideally the receiver would always produce full swing output signals with a constant delay, independent of input signal amplitude. By placing a passive filter between the V/I converter and the inverting amplifier stage, it is possible to amplify certain frequencies within the signal more than others, depending on the characteristics of the filter. This enables compensation for losses earlier in the signal path. Thus a device for enhancement of data receiver gain comprises of V/I converter, an amplifier and a passive filter placed between the amplifier and the V/I converter.